We recently had several computers that had problems with the computers hanging for several minutes at a time. At the time, it was hard to diagnose what the cause might be. We even thought that the hardware was failing in several locations.

The symptoms of the internet hanging also seemed to hang the entire computer. Accessing other applications was slow or inaccessible. We tried multiple browsers, new network cards, and ran the latest anti-malware, anti-spyware, and anti-virus scans all with no success.

In the end we removed Microsoft Security Essentials and our problem went away. There were a few posts regarding problems with Symantec Workspace Virtualization and Microsoft Security Essentials. In our case, we did have the Symantec Workspace Virtualization application installed but needed it for other applications.

Microsoft Security Essentials had worked flawlessly up until this point and is considered a reliable anti-virus application. We chose AVG Free as an alternative anti-virus. This application is also free and allowed us to keep the virtualization software.

Note: There does not seem to be anyway to disable Microsoft Security Essentials. Because of this, you need to uninstall to see if this fixes your problem.

AVG Free, http://free.avg.com/us-en/download-avg-anti-virus-free
Microsoft Security Essentials, http://www.microsoft.com/security_essentials/